Sound record and process of producing the same



Nov. 10, 1936. I F. .1. DOFSEN 2,060,287

SOUND RECORD AND PROCESS OF PRODUCING THE SAME Filed May 29, 1935 F'IIS IL INVENTOR.

F/OS/O 00/3627 ATTORNEY.

Patented Nov. 10, 1936 UNITED STATES PATENT OFFICE SOUND RECORD AND PROCESS OF PRODUCING THE SAME Floyd J. Dofsen, San Francisco, Calif.

Application May 29, 1935, Serial No. 23,983

4 Claims. (01. 274-43) This invention relates to a sound record and a process of producing a sound record for use'in small reproducing mechanisms, such as novelties,

especially those in which the sound record takes the form of a tape of flexible material.

An object of my invention is to produce tape sound records in large quantities economically.

Another object of my invention is to produce a sound record in which thematrix for producing the-record is not unduly distorted during its normal life. 1

An additional object of my invention is to provide a sound record which has a, raised sound track thereon.

A further object of my invention is to provid a process of producing a sound record which will I afford a raised track without utilizing an excess of material.

The foregoing and other objects are attained in the embodiment of the invention illustrated in the drawing, in which- Fig. 1 is a side elevation, partly in section, of a small sound reproducer incorporating the sound record of my invention.

Fig. 2 is a diagram to illustrate the process of my invention.

Fig. 3 is a cross-section of the tape within the forming rolls.

Fig. 4 is a cross-section of my sound record on an enlarged scale.

The sound record of my invention preferably comprises a strip of flexible material, thereby providing' a tape, which has a displaced portion the projecting part of which carries a sound track and the depressed portion of whichis substantially complementary to the raised portion. The process of my invention includes producing such sound record by the simultaneous impression of a sound track on a displaced portion of a tape while the tape is soft, and subsequently permitting the impressed and displaced tape to harden for use.

The sound record of my invention is useful in very widely varying environments, but is especially applicable for use in conjunction with a novelty or small sound reproducer such as is shown in Fig. 1. The device includes a box 6 of circular-cylindrical contour, having a sound dispersing aperture 1 in the front face thereof and a small aperture 8 in the rear face or diaphragm 9 thereof for the reception of the knotted end ll of a sound record l2. For operation, the box 6 is held between the thumb and forefinger of a ,user, who grips therecord l2 between the index finger and the thumbnail of the opposite hand. When he advances his thumbnail at a constant speed over the record, vibrations of the diaphragm 9 are produced, so that audible signals emanate from the aperture 1. Usually a short sentence is impressed upon the sound record l2 and is reproduced each time the userjretraces his thumb- 5 nail over the sound track.

' In accordance with my invention, I preferably provide that the sound record l2 be constructed of celluloid or comparable flexible material, in the shape of a relatively long, narrow, flat strip. 10 The tape so formed is preferably provided withan upstanding ridge l3 extending longitudinally of the tape and located centrally between the sides thereof to afford lands l4 and I 6. The ridge I3 is generally rectangular in cross-section and up- 15 stands from the general plane of thelands l4 and I6 in a predetermined amount I! which in one instance is approximately 4/1000ths of an inch. The upstanding ridge l3 on its face carries undulations l8 which represent the sound waves and together constitute the sound track, generally designated l9.

In accordance with my invention I preferably displace the material for the upstanding ridge [3 by providing a complementary groove 2I' on 25 the opposite face of the tape I2, which groove is substantially rectangular in cross-section and corresponds almost exactly to the ridge l3, except for the fact that the height 22 of the groove is substantially more than the height of the" 30 ridge IS, in one practical instance being approximately 6/ 1000ths of an inch. The resulting displaced central portion 23 of the tape is consequently of lesser thickness than either of the side portions beneath the lands l4 and I6. 35

In accordance with my invention, I preferably provide my sound record by a process especially, illustrated in Figs. 2 and 3. As shown in these figures, a strip 26 of celluloid or comparable material, of sufficient width to provide a plurality 40 (for instance, twelve) of finished sound records, is immersed in a bath 21 of warm water, so that the material is softened. The strip 26 is then fed between a pair of rolls 28 and 29, which turn upon their axes at the same rate but in opposite 45 directions. The upper roll '28 is provided with a depressed portion 3| in which are anchored the ends 32 of an electrolytically formed sound die 33. This die in cross-section is 'a thin sheet of metal, usually copper, carrying the complement 50 of the sound track thereon in a groove 3!, which is duplicated or varied for each of the plurality of strips with which it is intended to contact.

. The die 33 is wrapped around the roller 28 and is confined between side flanges 35 and 36 on 55 the roller 28, which hold the die accurately in position. The roller 29 on its periphery is provided with ridges 38, in contour corresponding to the grooves II, and being provided one for each of the plurality of records.

The softened tape is fed through the rotating rollers 28 and 28, beginning with the beginning of the die 33, and simultaneously the central portion of the record or tape is displaced to provide the central portion 23' and the sound track I9 is impressed in the surface of each of the records. Since the pressure between the rollers is confined to the central portion 23 of the tape,

there is no tendency to stretch or otherwise distort the thin die 33 which otherwise would be the case after protracted use. The die 33 is therefore useful almost indefinitely.

During the impression the heat contained in the warmed and softened tape is imparted to the relatively cool rollers 28 and 29, so that simultaneously, or substantially so, the displaced and impressed tape is hardened. As they emerge from the rollers 28 and 29, or subsequently if desired, the individual sound records are out apart at the places indicated by the broken lines 31 in Fig. 3 to provide the individual sound records as illustrated in Fig. 1, each of which is then knotted to form an anchor II for use in the device shown in Fig. 1. I claim:

1. A sound record comprising a strip of fiexible material having a straight longitudinal ridge of uniform width projecting from one side thereof and bearing the sound track, and a straight longitudinal groove on the other side thereof in substantial registry with said ridge.

2. A sound record comprising a flexible tape having its central portion offset from the side portions thereof to form an elevated rectilinear rib of uniform width with the sound track on said projecting central portion.

3. A sound record comprising a flexible tape having a ridge of a predetermined height and width on one side thereof bearing the sound track and having a complementary groove of lesser height on the other side thereof.

4. The process of producing a sound record which comprises advancing a tape to receive the sound track, and simultaneously impressing a sound track of fixed width on one side of said advancing tape and impressing a complementary groove having said fixed width on the other side 28 of said advancing tape.

FLOYD J. DOFSEN. 

